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One of the most serious problems of the Process Industry is that when planning the maintenance of the heat exchangers is not applied the methodologies based on economic criteria to optimize periods of cleaning surfaces resulting in additional costs for the company and for the country. This work develops and proposes a methodical based on the criterion of Minimum Cost for determining the optimal cleaning period. It is given an example of application of this method to the case of intercoolers of a centrifugal compressor with a high fouling level.It occurs this because is used sea water with many microorganisms as cooling agent which severely embeds transfer surfaces of side water. The methodology employed can be generalized to other applications. [ABSTRACT FROM AUTHOR]

Genetic resources constitute a national wealth and a guarantee to preserve plant life and diversity alive in the planet. Many places in the world are involved in their conservation, and the biggest germplasm bank of tropical roots and tubers in Latin America is found at the Research Institute of Tropical root and tuber crops. So, it resulted essential to develop an informatic application that contributes to control, to storage, to manage and to disseminate the information needed. As a valuable tool for researches, a software and respective data bases were created to control and to manage the information on the characters to be evaluated in the crops: cassava (Manihot esculenta Crantz), sweet potato (Ipomoea batatas (L.) Lam), aroids (Xanthosoma spp. and Colocasia esculenta Schott) and yam (Dioscorea spp.). [ABSTRACT FROM AUTHOR]

The present work aims at determining the clustering combination method that better fits the non-supervised classification of germplasm banks, as well as the validation index which more efficiently determines the optimal number of agglomerative hierarchical clusters. Mixed variables Gower metric was used in the research and the solutions coming out of the diverse clustering methods were combined so as to obtain a consensus structure. The strength of the clusters obtained by the clustering methods out of the data was evaluated using the agglomerative coefficient and the consensus conglomerate with the RV index. The optimal conglomerate number is obtained using five validation indexes which didn't bring about a homogeneous result. The better consensus structure for data base was obtained using the Manhattan method. Functions implemented in R programming language were used. This analysis strategy was used for the first time for the taxonomic classification of Cuban collections of new cocoyam (Xanthosoma spp.) and banana (Musa spp.) germplasm. [ABSTRACT FROM AUTHOR]

This study aims to compare the performance of four hierarchical clustering methods on several data structures to determine which method and topology is more consistent in classifying a taro (Xanthosoma spp.) genotype group and plantains (Musa spp.) from their characteristic traits. In the first method, a study is carried out on the Gower metric method for mixed variables which is combined with four other agglomeration methods and the second integrate transformed qualitative variables through multiple correspondence analysis with standardized quantitative variables, in a clustering analysis using, like the above, four agglomeration methods: average, Ward or minimum variance, Complete Linkage Agglomerative Clustering and Single Linkage Agglomerative Clustering combining at the same time with two distance measurements (Euclidean and Manhattan). Different structures were evaluated with the cophenetic correlation coefficient. For different analysis, implemented functions were used on the basis of the R programming language. In this research, it was determined that for both procedures with Gower and Euclidean distance measures, the average agglomeration method maintains better stability in the structures obtained. [ABSTRACT FROM AUTHOR]

Pumpkin is a crop that is gaining an increasing socioeconomic importance from the food security and so, there is a need to increase yield and quality through the generation and/or improvement of production technologies. In order to develop a tool for spreading knowledge on pumpkin crop, a data collection including scientific results, as well as, a video on an integral technology was carried out. Multimedia is implemented through outstanding tools such as Macromedia® Dreamweaver® MX 6 and Macromedia® FireworksMX 6. Powerful computational techniques were used and hypertexts were adequately applied. Multimedia permits a rapid and easy access to the information with a friendly interface, visually attractive and a careful use of the language. It results in an excellent informative and didactic medium that combines texts, images, graphics and diagrams and constitutes an enjoyable and outstanding method to promote and to disseminate scientific results and to exchange information. [ABSTRACT FROM AUTHOR]